Butternut > Trunk/Branches > Sunken, cracked or discolored areas along branches or trunk
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- Crown dieback that expands each year can be seen from a distance
- Cankers appear as multiple cracks in bark along trunk and branches
- Older cankers open into a barkless oval with ridges of wound wood on the edges
- Wood is stained dark brown to black underneath cankers
- Cankers quickly kill twigs and small branches while trunk cankers grow for several years
- Sprouts may form below cankers
- After several years, trees die
- Common on butternut, very rare on black walnut
- More information on Butternut canker...
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Perennial nectria canker
- Early canker symptoms are small and difficult to see, usually forming a darkened, depressed area beneath smooth, young bark
- Sunken round to oval cankers with target shaped ridges of barkless wood on large branches or main trunk
- Red to reddish orange raised cushion like bumps can occasionally be seen on the edge of the canker
- Dead branches and twigs killed by girdling cankers
- More information on Perennial nectria canker...
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- Vertical splits or sunken dead areas of trunk or branches that are primarily on the south and southwest side
- Occurs during winter, often noticed early spring
- More information on Frost canker...
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Flat headed apple tree borer
- Older tunnels cause cracks in bark, froth oozes from openings
- Infested areas of tree show sunken, darkened areas of bark
- Larvae tunnel under bark of large branches and trunk
- Can cause dieback or entire tree can be killed, especially young trees
- Larvae is yellow with no legs
- Adult is ¼ to ½ inch long, flattened beetle, ranging from metallic brown to dull gray
- More information on Flat-headed apple tree borer...